If you want to slim your thighs, cardiovascular exercise can get you closer to your goal. Although you can't spot-reduce one area of your body, you can focus on reducing overall body fat, and eventually, excess fat on your thighs will also reduce. The type of cardio you do should increase your heart rate and can depend on various factors including convenience, effectiveness and your personal fitness level. For optimal results, do 300 minutes of moderate cardio per week, as recommended by the Centers for Disease Control and Prevention.

Understanding Weight Loss

To slim your upper legs, you must create a caloric deficit. This means you should burn more calories than you consume every day. To lose 1 pound of fat in a week, you must create a deficit of 3,500 calories. You can achieve this by consuming fewer calories and by exercising -- cardio burns calories while strength training builds muscle tissue, which increases your resting metabolic rate, resulting in caloric burn even after your workout.

Types of Cardio

Cardiovascular exercise commonly involves movement of your legs and can be done with or without exercise equipment. Cardio in which you carry your body weight, also known as weight-bearing cardio, is more strenuous on your joints, knees and back. This includes exercises such as running, jumping rope and climbing stairs. To avoid the excess stress and still burn calories, do non-weight-bearing cardio, such as rowing, swimming or bicycling. Regardless of which type of cardio you do, choose exercises that you can continue in the long run to maintain your results.

Burning Calories

The number of calories you burn during cardiovascular exercise depends on the type of exercise you're doing and the intensity you're exercising at. For faster thigh-slimming results, go running, jump rope or exercise on a stair climber. These exercises are top calorie burners, and when you do them at such a vigorous intensity that you can't converse, you can cut your exercise time in half. Interval training, in which you do quick bursts of intense cardio followed by rest periods at a lower intensity, can also increase caloric burn and add variety to your routine.

Considerations

Before starting a cardiovascular exercise routine, consult a doctor, especially if you have injuries or health conditions. Gradually build up your exercise routine. If your goal is to do cardio for one hour per day, start with a 15-minute workout, and as you get stronger and increase your endurance, gradually increase the duration. Targeted strengthening exercises, such as lunges and squats, can also be beneficial because they increase muscle tissue, which takes up less space than fat so your thighs will appear slimmer.

About the Author

Kimberly Caines is a well traveled model, writer and licensed physical fitness trainer who was first published in 1997. Her work has appeared in the Dutch newspaper "De Overschiese Krant" and on various websites. Caines holds a degree in journalism from Mercurius College in Holland and is writing her first novel.